[PATCH] drm/i915: Fix legacy gamma lut updates in Linux 4.7-rc6

[PATCH] drm/i915: Fix legacy gamma lut updates in Linux 4.7-rc6

[Mario Kleiner]

Updating legacy gamma tables, e.g., via RandR doesn't work at all
as of Linux 4.7-rc6.

Reason seems to be that the required call to
drm_atomic_helper_commit_planes_on_crtc is skipped in
intel_atomic_commit after userspace set new gamma tables,
because neither crtc->state->planes_changed nor
update_pipe (= pipe_config->update_pipe) are true.

Removing the check for planes_changed || update_pipe fixes
gamma table updates.

The code for Linux 4.8 drm-next has changed a lot in that area
wrt. 4.7, but the new code for 4.8 also removed those checks
and calls drm_atomic_helper_commit_planes_on_crtc unconditionally,
and legacy gamma lut updates work on drm-next, so this seems to be
the right solution.

Tested also shutdown/reboot, suspend/resume, (un-)plugging displays,
mode switches for resolution/refresh rate, display rotation, and
page-flipping/pageflip timing on Intel HD Ironlake to confirm the
fix apparently doesn't break anything under X11.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/intel_display.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 04452cf..eb8fb36 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13685,7 +13685,6 @@ static int intel_atomic_commit(struct drm_device *dev,
 		bool modeset = needs_modeset(crtc->state);
 		struct intel_crtc_state *pipe_config =
 			to_intel_crtc_state(crtc->state);
-		bool update_pipe = !modeset && pipe_config->update_pipe;
 
 		if (modeset && crtc->state->active) {
 			update_scanline_offset(to_intel_crtc(crtc));
@@ -13699,8 +13698,7 @@ static int intel_atomic_commit(struct drm_device *dev,
 		    drm_atomic_get_existing_plane_state(state, crtc->primary))
 			intel_fbc_enable(intel_crtc);
 
-		if (crtc->state->active &&
-		    (crtc->state->planes_changed || update_pipe))
+		if (crtc->state->active)
 			drm_atomic_helper_commit_planes_on_crtc(old_crtc_state);
 
 		if (pipe_config->base.active && needs_vblank_wait(pipe_config))
-- 
2.7.0

Re: [PATCH] drm/i915: Fix legacy gamma lut updates in Linux 4.7-rc6

[Lionel Landwerlin]

Hi Mario,

There was a couple of patch to fix this issue :

https://patchwork.freedesktop.org/series/5467/
https://patchwork.freedesktop.org/series/5466/

I tested this late last week on drm-intel-nightly, it seems a series of 
revert fixed most of the issues.

Cheers,

-
Lionel

On 12/07/16 11:33, Mario Kleiner wrote:
> Updating legacy gamma tables, e.g., via RandR doesn't work at all
> as of Linux 4.7-rc6.
>
> Reason seems to be that the required call to
> drm_atomic_helper_commit_planes_on_crtc is skipped in
> intel_atomic_commit after userspace set new gamma tables,
> because neither crtc->state->planes_changed nor
> update_pipe (= pipe_config->update_pipe) are true.
>
> Removing the check for planes_changed || update_pipe fixes
> gamma table updates.
>
> The code for Linux 4.8 drm-next has changed a lot in that area
> wrt. 4.7, but the new code for 4.8 also removed those checks
> and calls drm_atomic_helper_commit_planes_on_crtc unconditionally,
> and legacy gamma lut updates work on drm-next, so this seems to be
> the right solution.
>
> Tested also shutdown/reboot, suspend/resume, (un-)plugging displays,
> mode switches for resolution/refresh rate, display rotation, and
> page-flipping/pageflip timing on Intel HD Ironlake to confirm the
> fix apparently doesn't break anything under X11.
>
> Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>   drivers/gpu/drm/i915/intel_display.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 04452cf..eb8fb36 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -13685,7 +13685,6 @@ static int intel_atomic_commit(struct drm_device *dev,
>   		bool modeset = needs_modeset(crtc->state);
>   		struct intel_crtc_state *pipe_config =
>   			to_intel_crtc_state(crtc->state);
> -		bool update_pipe = !modeset && pipe_config->update_pipe;
>   
>   		if (modeset && crtc->state->active) {
>   			update_scanline_offset(to_intel_crtc(crtc));
> @@ -13699,8 +13698,7 @@ static int intel_atomic_commit(struct drm_device *dev,
>   		    drm_atomic_get_existing_plane_state(state, crtc->primary))
>   			intel_fbc_enable(intel_crtc);
>   
> -		if (crtc->state->active &&
> -		    (crtc->state->planes_changed || update_pipe))
> +		if (crtc->state->active)
>   			drm_atomic_helper_commit_planes_on_crtc(old_crtc_state);
>   
>   		if (pipe_config->base.active && needs_vblank_wait(pipe_config))

Re: [PATCH] drm/i915: Fix legacy gamma lut updates in Linux 4.7-rc6

[Mario Kleiner]

On 07/12/2016 12:50 PM, Lionel Landwerlin wrote:
> Hi Mario,
>

Hi Lionel,

> There was a couple of patch to fix this issue :
>
> https://patchwork.freedesktop.org/series/5467/
> https://patchwork.freedesktop.org/series/5466/
>

Looking at them they should fix the issue, but they seem to be stuck in 
review?

> I tested this late last week on drm-intel-nightly, it seems a series of
> revert fixed most of the issues.
>

You mean something else has fixed legacy gamma updates, as i can't find 
above patches applied on drm-intel-nightly?

Are those fixes supposed to be already part of 4.7-rc7, the final rc afaik?

thanks,
-mario


> Cheers,
>
> -
> Lionel
>
> On 12/07/16 11:33, Mario Kleiner wrote:
>> Updating legacy gamma tables, e.g., via RandR doesn't work at all
>> as of Linux 4.7-rc6.
>>
>> Reason seems to be that the required call to
>> drm_atomic_helper_commit_planes_on_crtc is skipped in
>> intel_atomic_commit after userspace set new gamma tables,
>> because neither crtc->state->planes_changed nor
>> update_pipe (= pipe_config->update_pipe) are true.
>>
>> Removing the check for planes_changed || update_pipe fixes
>> gamma table updates.
>>
>> The code for Linux 4.8 drm-next has changed a lot in that area
>> wrt. 4.7, but the new code for 4.8 also removed those checks
>> and calls drm_atomic_helper_commit_planes_on_crtc unconditionally,
>> and legacy gamma lut updates work on drm-next, so this seems to be
>> the right solution.
>>
>> Tested also shutdown/reboot, suspend/resume, (un-)plugging displays,
>> mode switches for resolution/refresh rate, display rotation, and
>> page-flipping/pageflip timing on Intel HD Ironlake to confirm the
>> fix apparently doesn't break anything under X11.
>>
>> Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
>> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>> ---
>>   drivers/gpu/drm/i915/intel_display.c | 4 +---
>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_display.c
>> b/drivers/gpu/drm/i915/intel_display.c
>> index 04452cf..eb8fb36 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -13685,7 +13685,6 @@ static int intel_atomic_commit(struct
>> drm_device *dev,
>>           bool modeset = needs_modeset(crtc->state);
>>           struct intel_crtc_state *pipe_config =
>>               to_intel_crtc_state(crtc->state);
>> -        bool update_pipe = !modeset && pipe_config->update_pipe;
>>           if (modeset && crtc->state->active) {
>>               update_scanline_offset(to_intel_crtc(crtc));
>> @@ -13699,8 +13698,7 @@ static int intel_atomic_commit(struct
>> drm_device *dev,
>>               drm_atomic_get_existing_plane_state(state, crtc->primary))
>>               intel_fbc_enable(intel_crtc);
>> -        if (crtc->state->active &&
>> -            (crtc->state->planes_changed || update_pipe))
>> +        if (crtc->state->active)
>>               drm_atomic_helper_commit_planes_on_crtc(old_crtc_state);
>>           if (pipe_config->base.active && needs_vblank_wait(pipe_config))
>
>

Re: [PATCH] drm/i915: Fix legacy gamma lut updates in Linux 4.7-rc6

[Lionel Landwerlin]

On 12/07/16 13:11, Mario Kleiner wrote:
> On 07/12/2016 12:50 PM, Lionel Landwerlin wrote:
>> Hi Mario,
>>
>
> Hi Lionel,
>
>> There was a couple of patch to fix this issue :
>>
>> https://patchwork.freedesktop.org/series/5467/
>> https://patchwork.freedesktop.org/series/5466/
>>
>
> Looking at them they should fix the issue, but they seem to be stuck 
> in review?
>
>> I tested this late last week on drm-intel-nightly, it seems a series of
>> revert fixed most of the issues.
>>
>
> You mean something else has fixed legacy gamma updates, as i can't 
> find above patches applied on drm-intel-nightly?

This revert on drm-intel-nightly seems to have fixed the problem :

https://cgit.freedesktop.org/drm-intel/commit/drivers/gpu/drm/i915?id=e42aeef1237b7c969a77b7f726c50f6cb832185f

>
> Are those fixes supposed to be already part of 4.7-rc7, the final rc 
> afaik?

I haven't seen it on 4.7-rc7.

>
> thanks,
> -mario
>
>
>> Cheers,
>>
>> -
>> Lionel
>>
>> On 12/07/16 11:33, Mario Kleiner wrote:
>>> Updating legacy gamma tables, e.g., via RandR doesn't work at all
>>> as of Linux 4.7-rc6.
>>>
>>> Reason seems to be that the required call to
>>> drm_atomic_helper_commit_planes_on_crtc is skipped in
>>> intel_atomic_commit after userspace set new gamma tables,
>>> because neither crtc->state->planes_changed nor
>>> update_pipe (= pipe_config->update_pipe) are true.
>>>
>>> Removing the check for planes_changed || update_pipe fixes
>>> gamma table updates.
>>>
>>> The code for Linux 4.8 drm-next has changed a lot in that area
>>> wrt. 4.7, but the new code for 4.8 also removed those checks
>>> and calls drm_atomic_helper_commit_planes_on_crtc unconditionally,
>>> and legacy gamma lut updates work on drm-next, so this seems to be
>>> the right solution.
>>>
>>> Tested also shutdown/reboot, suspend/resume, (un-)plugging displays,
>>> mode switches for resolution/refresh rate, display rotation, and
>>> page-flipping/pageflip timing on Intel HD Ironlake to confirm the
>>> fix apparently doesn't break anything under X11.
>>>
>>> Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
>>> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>>> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
>>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>>> ---
>>>   drivers/gpu/drm/i915/intel_display.c | 4 +---
>>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/intel_display.c
>>> b/drivers/gpu/drm/i915/intel_display.c
>>> index 04452cf..eb8fb36 100644
>>> --- a/drivers/gpu/drm/i915/intel_display.c
>>> +++ b/drivers/gpu/drm/i915/intel_display.c
>>> @@ -13685,7 +13685,6 @@ static int intel_atomic_commit(struct
>>> drm_device *dev,
>>>           bool modeset = needs_modeset(crtc->state);
>>>           struct intel_crtc_state *pipe_config =
>>>               to_intel_crtc_state(crtc->state);
>>> -        bool update_pipe = !modeset && pipe_config->update_pipe;
>>>           if (modeset && crtc->state->active) {
>>>               update_scanline_offset(to_intel_crtc(crtc));
>>> @@ -13699,8 +13698,7 @@ static int intel_atomic_commit(struct
>>> drm_device *dev,
>>>               drm_atomic_get_existing_plane_state(state, 
>>> crtc->primary))
>>>               intel_fbc_enable(intel_crtc);
>>> -        if (crtc->state->active &&
>>> -            (crtc->state->planes_changed || update_pipe))
>>> +        if (crtc->state->active)
>>> drm_atomic_helper_commit_planes_on_crtc(old_crtc_state);
>>>           if (pipe_config->base.active && 
>>> needs_vblank_wait(pipe_config))
>>
>>
>

Re: [PATCH] drm/i915: Fix legacy gamma lut updates in Linux 4.7-rc6

[Mario Kleiner]

On 07/12/2016 05:02 PM, Lionel Landwerlin wrote:
> On 12/07/16 13:11, Mario Kleiner wrote:
>> On 07/12/2016 12:50 PM, Lionel Landwerlin wrote:
>>> Hi Mario,
>>>
>>
>> Hi Lionel,
>>
>>> There was a couple of patch to fix this issue :
>>>
>>> https://patchwork.freedesktop.org/series/5467/
>>> https://patchwork.freedesktop.org/series/5466/
>>>
>>
>> Looking at them they should fix the issue, but they seem to be stuck
>> in review?
>>
>>> I tested this late last week on drm-intel-nightly, it seems a series of
>>> revert fixed most of the issues.
>>>
>>
>> You mean something else has fixed legacy gamma updates, as i can't
>> find above patches applied on drm-intel-nightly?
>
> This revert on drm-intel-nightly seems to have fixed the problem :
>
> https://cgit.freedesktop.org/drm-intel/commit/drivers/gpu/drm/i915?id=e42aeef1237b7c969a77b7f726c50f6cb832185f
>

Ok, with that intel-nightly looks like drm-next for 4.8 and that indeed 
has working lut updates in my testing. My own patch was motivated by the 
way the implementation is done in intel_atomic_commit_tail() from drm-next.

>
>>
>> Are those fixes supposed to be already part of 4.7-rc7, the final rc
>> afaik?
>
> I haven't seen it on 4.7-rc7.
>

I just checked Linus tree for 4.7-rc7 and there the code in 
intel_display.c didn't receive any updates since 13 days and looks like 
the broken code from rc6 which according to my testing doesn't work.

So i'd assume legacy gamma table updates are broken in Linux 4.7 final 
rc atm. Couldn't test, because for some weird reason 4.7-rc7 doesn't 
even boot on my laptop :( - However i got that via a quick install from 
Ubuntu's mainline ppa so it could be some unrelated problem with their 
ppa builds.

I think either my patch would fix it, but is untested wrt. nuclear 
pageflip, or those two patches you referenced, which apparently didn't 
move forward.

What now?
-mario

>>
>> thanks,
>> -mario
>>
>>
>>> Cheers,
>>>
>>> -
>>> Lionel
>>>
>>> On 12/07/16 11:33, Mario Kleiner wrote:
>>>> Updating legacy gamma tables, e.g., via RandR doesn't work at all
>>>> as of Linux 4.7-rc6.
>>>>
>>>> Reason seems to be that the required call to
>>>> drm_atomic_helper_commit_planes_on_crtc is skipped in
>>>> intel_atomic_commit after userspace set new gamma tables,
>>>> because neither crtc->state->planes_changed nor
>>>> update_pipe (= pipe_config->update_pipe) are true.
>>>>
>>>> Removing the check for planes_changed || update_pipe fixes
>>>> gamma table updates.
>>>>
>>>> The code for Linux 4.8 drm-next has changed a lot in that area
>>>> wrt. 4.7, but the new code for 4.8 also removed those checks
>>>> and calls drm_atomic_helper_commit_planes_on_crtc unconditionally,
>>>> and legacy gamma lut updates work on drm-next, so this seems to be
>>>> the right solution.
>>>>
>>>> Tested also shutdown/reboot, suspend/resume, (un-)plugging displays,
>>>> mode switches for resolution/refresh rate, display rotation, and
>>>> page-flipping/pageflip timing on Intel HD Ironlake to confirm the
>>>> fix apparently doesn't break anything under X11.
>>>>
>>>> Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
>>>> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>>>> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
>>>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>>>> ---
>>>>   drivers/gpu/drm/i915/intel_display.c | 4 +---
>>>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/intel_display.c
>>>> b/drivers/gpu/drm/i915/intel_display.c
>>>> index 04452cf..eb8fb36 100644
>>>> --- a/drivers/gpu/drm/i915/intel_display.c
>>>> +++ b/drivers/gpu/drm/i915/intel_display.c
>>>> @@ -13685,7 +13685,6 @@ static int intel_atomic_commit(struct
>>>> drm_device *dev,
>>>>           bool modeset = needs_modeset(crtc->state);
>>>>           struct intel_crtc_state *pipe_config =
>>>>               to_intel_crtc_state(crtc->state);
>>>> -        bool update_pipe = !modeset && pipe_config->update_pipe;
>>>>           if (modeset && crtc->state->active) {
>>>>               update_scanline_offset(to_intel_crtc(crtc));
>>>> @@ -13699,8 +13698,7 @@ static int intel_atomic_commit(struct
>>>> drm_device *dev,
>>>>               drm_atomic_get_existing_plane_state(state,
>>>> crtc->primary))
>>>>               intel_fbc_enable(intel_crtc);
>>>> -        if (crtc->state->active &&
>>>> -            (crtc->state->planes_changed || update_pipe))
>>>> +        if (crtc->state->active)
>>>> drm_atomic_helper_commit_planes_on_crtc(old_crtc_state);
>>>>           if (pipe_config->base.active &&
>>>> needs_vblank_wait(pipe_config))
>>>
>>>
>>
>

Re: [PATCH] drm/i915: Fix legacy gamma lut updates in Linux 4.7-rc6

[Mario Kleiner]

Ok, so legacy gamma table updates are completely broken for Intel on 
Linux-4.7-rc7, the final release candidate.

The good news is that applying Lionel's patch

"drm/i915: add missing condition for committing planes on crtc"

from

https://patchwork.freedesktop.org/patch/89111/

fixes it nicely. The patch currently applies cleanly to drm-fixes and 
drm-next and is

Reviewed-and-tested-by: Mario Kleiner <mario.kleiner.de@gmail.com>


When we are at it, could somebody please look at that updated series of 
my Displayport color depth fixes ("EDID/DP fixes for proper bpc 
detection of displays.") i sent out a week ago?

Especially pulling patch 2/5 "[PATCH 2/5] drm/i915/dp: Revert 
"drm/i915/dp: fall back to 18 bpp when sink capability is unknown" would 
be important, as that bug introduced a regression for Intel + DP + 
legacy DP converters into stable kernels which is very serious for users 
of scientific/medical display equipment, especially as the failures can 
easily go unnoticed during normal equipment tests, but would introduce 
the equivalent of "silent data corruption" into their measured 
scientific data, which is not a great experience given that collecting 
such data can easily take half a year of work time and ten-thousands of 
euros of wasted research funding.

Patches 3 and 4 contain changes Daniel asked me to do, patch 5 would be 
good to safe-guard against similar issues in the future.

thanks,
-mario

On 07/12/2016 12:50 PM, Lionel Landwerlin wrote:
> Hi Mario,
>
> There was a couple of patch to fix this issue :
>
> https://patchwork.freedesktop.org/series/5467/
> https://patchwork.freedesktop.org/series/5466/
>
> I tested this late last week on drm-intel-nightly, it seems a series of
> revert fixed most of the issues.
>
> Cheers,
>
> -
> Lionel
>
> On 12/07/16 11:33, Mario Kleiner wrote:
>> Updating legacy gamma tables, e.g., via RandR doesn't work at all
>> as of Linux 4.7-rc6.
>>
>> Reason seems to be that the required call to
>> drm_atomic_helper_commit_planes_on_crtc is skipped in
>> intel_atomic_commit after userspace set new gamma tables,
>> because neither crtc->state->planes_changed nor
>> update_pipe (= pipe_config->update_pipe) are true.
>>
>> Removing the check for planes_changed || update_pipe fixes
>> gamma table updates.
>>
>> The code for Linux 4.8 drm-next has changed a lot in that area
>> wrt. 4.7, but the new code for 4.8 also removed those checks
>> and calls drm_atomic_helper_commit_planes_on_crtc unconditionally,
>> and legacy gamma lut updates work on drm-next, so this seems to be
>> the right solution.
>>
>> Tested also shutdown/reboot, suspend/resume, (un-)plugging displays,
>> mode switches for resolution/refresh rate, display rotation, and
>> page-flipping/pageflip timing on Intel HD Ironlake to confirm the
>> fix apparently doesn't break anything under X11.
>>
>> Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
>> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>> ---
>>   drivers/gpu/drm/i915/intel_display.c | 4 +---
>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_display.c
>> b/drivers/gpu/drm/i915/intel_display.c
>> index 04452cf..eb8fb36 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -13685,7 +13685,6 @@ static int intel_atomic_commit(struct
>> drm_device *dev,
>>           bool modeset = needs_modeset(crtc->state);
>>           struct intel_crtc_state *pipe_config =
>>               to_intel_crtc_state(crtc->state);
>> -        bool update_pipe = !modeset && pipe_config->update_pipe;
>>           if (modeset && crtc->state->active) {
>>               update_scanline_offset(to_intel_crtc(crtc));
>> @@ -13699,8 +13698,7 @@ static int intel_atomic_commit(struct
>> drm_device *dev,
>>               drm_atomic_get_existing_plane_state(state, crtc->primary))
>>               intel_fbc_enable(intel_crtc);
>> -        if (crtc->state->active &&
>> -            (crtc->state->planes_changed || update_pipe))
>> +        if (crtc->state->active)
>>               drm_atomic_helper_commit_planes_on_crtc(old_crtc_state);
>>           if (pipe_config->base.active && needs_vblank_wait(pipe_config))
>
>